Malmö University Publications
Change search
Link to record
Permanent link

Direct link
Publications (6 of 6) Show all publications
Psotta, C., Nilsson, E. J., Sjöberg, T. & Falk, M. (2023). Bacteria-Infected Artificial Urine Characterization Based on a Combined Approach Using an Electronic Tongue Complemented with 1H-NMR and Flow Cytometry. Biosensors, 13(10), 916-916
Open this publication in new window or tab >>Bacteria-Infected Artificial Urine Characterization Based on a Combined Approach Using an Electronic Tongue Complemented with 1H-NMR and Flow Cytometry
2023 (English)In: Biosensors, E-ISSN 2079-6374, Vol. 13, no 10, p. 916-916Article in journal (Refereed) Published
Abstract [en]

The prevailing form of bacterial infection is within the urinary tract, encompassing a wide array of bacteria that harness the urinary metabolome for their growth. Through their metabolic actions, the chemical composition of the growth medium undergoes modifications as the bacteria metabolize urine compounds, leading to the subsequent release of metabolites. These changes can indirectly indicate the existence and proliferation of bacterial organisms. Here, we investigate the use of an electronic tongue, a powerful analytical instrument based on a combination of non-selective chemical sensors with a partial specificity for data gathering combined with principal component analysis, to distinguish between infected and non-infected artificial urine samples. Three prevalent bacteria found in urinary tract infections were investigated, Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis. Furthermore, the electronic tongue analysis was supplemented with 1H NMR spectroscopy and flow cytometry. Bacteria-specific changes in compound consumption allowed for a qualitative differentiation between artificial urine medium and bacterial growth.

Place, publisher, year, edition, pages
MDPI, 2023
Keywords
electronic tongue, bacterial detection, artificial urine, urinary tract infection, 1H-NMR, flow cytometry
National Category
Microbiology
Identifiers
urn:nbn:se:mau:diva-63142 (URN)10.3390/bios13100916 (DOI)001096540000001 ()37887109 (PubMedID)2-s2.0-85175044453 (Scopus ID)
Available from: 2023-10-13 Created: 2023-10-13 Last updated: 2024-04-11Bibliographically approved
Morin, M., Björklund, S., Nilsson, E. J. & Engblom, J. (2023). Bicontinuous Cubic Liquid Crystals as Potential Matrices for Non-Invasive Topical Sampling of Low-Molecular-Weight Biomarkers. Pharmaceutics, 15(8), Article ID 2031.
Open this publication in new window or tab >>Bicontinuous Cubic Liquid Crystals as Potential Matrices for Non-Invasive Topical Sampling of Low-Molecular-Weight Biomarkers
2023 (English)In: Pharmaceutics, ISSN 1999-4923, E-ISSN 1999-4923, Vol. 15, no 8, article id 2031Article in journal (Refereed) Published
Abstract [en]

Many skin disorders, including cancer, have inflammatory components. The non-invasive detection of related biomarkers could therefore be highly valuable for both diagnosis and follow up on the effect of treatment. This study targets the extraction of tryptophan (Trp) and its metabolite kynurenine (Kyn), two compounds associated with several inflammatory skin disorders. We furthermore hypothesize that lipid-based bicontinuous cubic liquid crystals could be efficient extraction matrices. They comprise a large interfacial area separating interconnected polar and apolar domains, allowing them to accommodate solutes with various properties. We concluded, using the extensively studied GMO-water system as test-platform, that the hydrophilic Kyn and Trp favored the cubic phase over water and revealed a preference for locating at the lipid-water interface. The interfacial area per unit volume of the matrix, as well as the incorporation of ionic molecules at the lipid-water interface, can be used to optimize the extraction of solutes with specific physicochemical characteristics. We also observed that the cubic phases formed at rather extreme water activities (>0.9) and that wearing them resulted in efficient hydration and increased permeability of the skin. Evidently, bicontinuous cubic liquid crystals constitute a promising and versatile platform for non-invasive extraction of biomarkers through skin, as well as for transdermal drug delivery.

Place, publisher, year, edition, pages
MDPI, 2023
Keywords
tryptophan, kynurenine, tryptophan-to-kynurenine ratio, cancer-related biomarkers, non-invasive extraction, bicontinuous cubic liquid crystal, bilayer partitioning, glycerol monooleate, DOTAP, X-ray diffraction, humidity scanning (HS) QCM-D
National Category
Pharmaceutical Chemistry
Identifiers
urn:nbn:se:mau:diva-62643 (URN)10.3390/pharmaceutics15082031 (DOI)001055274500001 ()37631245 (PubMedID)2-s2.0-85168893889 (Scopus ID)
Available from: 2023-09-18 Created: 2023-09-18 Last updated: 2023-10-19Bibliographically approved
Riaz, A., Gidvall, S., Prgomet, Z., Hernandez, A. R., Ruzgas, T., Nilsson, E. J., . . . Valetti, S. (2023). Three-Dimensional Oral Mucosal Equivalents as Models for Transmucosal Drug Permeation Studies. Pharmaceutics, 15(5), 1513-1513
Open this publication in new window or tab >>Three-Dimensional Oral Mucosal Equivalents as Models for Transmucosal Drug Permeation Studies
Show others...
2023 (English)In: Pharmaceutics, ISSN 1999-4923, E-ISSN 1999-4923, Vol. 15, no 5, p. 1513-1513Article in journal (Refereed) Published
Abstract [en]

Oral transmucosal administration, where drugs are absorbed directly through the non-keratinized, lining mucosa of the mouth, represents a solution to drug delivery with several advantages. Oral mucosal equivalents (OME) developed as 3D in vitro models are of great interest since they express the correct cell differentiation and tissue architecture, simulating the in vivo conditions better than monolayer cultures or animal tissues. The aim of this work was to develop OME to be used as a membrane for drug permeation studies. We developed both full-thickness (i.e., connective plus epithelial tissue) and split-thickness (i.e., only epithelial tissue) OME using non-tumor-derived human keratinocytes OKF6 TERT-2 obtained from the floor of the mouth. All the OME developed here presented similar transepithelial electrical resistance (TEER) values, comparable to the commercial EpiOral™. Using eletriptan hydrobromide as a model drug, we found that the full-thickness OME had similar drug flux to EpiOral™ (28.8 vs. 29.6 µg/cm2/h), suggesting that the model had the same permeation barrier properties. Furthermore, full-thickness OME showed an increase in ceramide content together with a decrease in phospholipids in comparison to the monolayer culture, indicating that lipid differentiation occurred due to the tissue-engineering protocols. The split-thickness mucosal model resulted in 4–5 cell layers with basal cells still undergoing mitosis. The optimum period at the air–liquid interface for this model was twenty-one days; after longer times, signs of apoptosis appeared. Following the 3R principles, we found that the addition of Ca2+, retinoic acid, linoleic acid, epidermal growth factor and bovine pituitary extract was important but not sufficient to fully replace the fetal bovine serum. Finally, the OME models presented here offer a longer shelf-life than the pre-existing models, which paves the way for the further investigation of broader pharmaceutical applications (i.e., long-term drug exposure, effect on the keratinocytes’ differentiation and inflammatory conditions, etc.).

Place, publisher, year, edition, pages
MDPI, 2023
Keywords
oral transmucosal delivery, oral mucosal equivalents, drug permeation, 3R principles, 3D in vitro models
National Category
Pharmaceutical Sciences
Identifiers
urn:nbn:se:mau:diva-61046 (URN)10.3390/pharmaceutics15051513 (DOI)000997495400001 ()37242755 (PubMedID)2-s2.0-85160448981 (Scopus ID)
Funder
The Crafoord Foundation, 20210937Knowledge Foundation, 20190010
Available from: 2023-06-19 Created: 2023-06-19 Last updated: 2023-08-15Bibliographically approved
Lind, T. K., Nilsson, E. J., Wyler, B., Scherer, D., Skansberger, T., Morin, M., . . . Engblom, J. (2021). Effects of ethylene oxide chain length on crystallization of polysorbate 80 and its related compounds. Journal of Colloid and Interface Science, 592, 468-484, Article ID S0021-9797(21)00078-3.
Open this publication in new window or tab >>Effects of ethylene oxide chain length on crystallization of polysorbate 80 and its related compounds
Show others...
2021 (English)In: Journal of Colloid and Interface Science, ISSN 0021-9797, E-ISSN 1095-7103, Vol. 592, p. 468-484, article id S0021-9797(21)00078-3Article in journal (Refereed) Published
Abstract [en]

As a result of the synthesis protocol polyoxyethylene sorbitan monooleate (polysorbate 80, PS80) is a highly complex mixture of compounds. PS80 was therefore separated into its main constituents, e.g. polyoxyethylene isosorbide esters and polyoxyethylene esters, as well as mono- di- and polyesters using preparative high-performance liquid chromatography. In this comprehensive study the individual components and their ethoxylation level were verified by matrix assisted laser desorption/ionization time-of-flight and their thermotropic behavior was analyzed using differential scanning calorimetry and X-ray diffraction. A distinct correlation was found between the average length of the ethylene oxide (EO) chains in the headgroup and the individual compounds' ability to crystallize. Importantly, a critical number of EO units required for crystallization of the headgroup was determined (6 EO units per chain or 24 per molecule). The investigation also revealed that the hydrocarbon tails only crystallize for polyoxyethylene sorbitan esters if saturated. PS80 is synthesized by reacting with approximately 20 mol of EO per mole of sorbitol, however, the number of EO units in the sorbitan ester in commercial PS80 products is higher than the expected 20 (5 EO units per chain). The complex behavior of all tested compounds revealed that if the amount of several of the linear by-products is reduced, the number of EO units in the chains will stay below the critical number and the product will not be able to crystallize by the EO chains.

Place, publisher, year, edition, pages
Elsevier, 2021
Keywords
Crystallization, Differential scanning calorimetry, Ethylene oxide chains, Liquid chromatography, Polysorbate 80, Thermotropic behavior
National Category
Physical Chemistry
Identifiers
urn:nbn:se:mau:diva-41655 (URN)10.1016/j.jcis.2021.01.065 (DOI)000634152600006 ()33711648 (PubMedID)2-s2.0-85102147545 (Scopus ID)
Available from: 2021-04-08 Created: 2021-04-08 Last updated: 2024-02-05Bibliographically approved
Falk, M., Nilsson, E. J., Cirovic, S., Tudosoiu, B. & Shleev, S. (2021). Wearable Electronic Tongue for Non-Invasive Assessment of Human Sweat. Sensors, 21(21), Article ID 7311.
Open this publication in new window or tab >>Wearable Electronic Tongue for Non-Invasive Assessment of Human Sweat
Show others...
2021 (English)In: Sensors, E-ISSN 1424-8220, Vol. 21, no 21, article id 7311Article in journal (Refereed) Published
Abstract [en]

Sweat is a promising biofluid in allowing for non-invasive sampling. Here, we investigate the use of a voltammetric electronic tongue, combining different metal electrodes, for the purpose of non-invasive sample assessment, specifically focusing on sweat. A wearable electronic tongue is presented by incorporating metal electrodes on a flexible circuit board and used to non-invasively monitor sweat on the body. The data obtained from the measurements were treated by multivariate data processing. Using principal component analysis to analyze the data collected by the wearable electronic tongue enabled differentiation of sweat samples of different chemical composition, and when combined with 1H-NMR sample differentiation could be attributed to changing analyte concentrations.

Place, publisher, year, edition, pages
MDPI, 2021
Keywords
electronic tongue, human sweat, non-invasive analysis, wearable sensors
National Category
Analytical Chemistry
Identifiers
urn:nbn:se:mau:diva-46850 (URN)10.3390/s21217311 (DOI)000719077700001 ()34770617 (PubMedID)2-s2.0-85118345498 (Scopus ID)
Available from: 2021-11-15 Created: 2021-11-15 Last updated: 2024-02-05Bibliographically approved
Nilsson, E. J., Lind, T. K., Scherer, D., Skansberger, T., Mortensen, K., Engblom, J. & Kocherbitov, V. (2020). Mechanisms of crystallisation in polysorbates and sorbitan esters. CrystEngComm, 22(22), 3840-3853
Open this publication in new window or tab >>Mechanisms of crystallisation in polysorbates and sorbitan esters
Show others...
2020 (English)In: CrystEngComm, ISSN 1466-8033, E-ISSN 1466-8033, Vol. 22, no 22, p. 3840-3853Article in journal (Refereed) Published
Abstract [en]

Polysorbates (PS), commonly known as Tween (TM), are some of the most extensively used excipients and protein stabilisers in biopharmaceutical products worldwide. It is stipulated in the pharmacopoeia specifications that these ethoxylated surfactants are complex mixtures comprised of a wealth of molecular species. While little is known about the propensity of PSs to crystallise, they are used in applications ranging from food products, cosmetics, different types of drug dosage forms like creams and oral products to parenteral applications. However, in recent years a range of issues and safety concerns have appeared when using them for stabilising biopharmaceutical products including precipitation, particle formation, and adverse biological effects. Therefore, the aim of this study was to thoroughly characterise the thermotropic behaviour and mechanism of crystallisation of polysorbates with different hydrocarbon tails and their non-ethoxylated sorbitan ester equivalents for comparison. A systematic and comprehensive product characterisation was carried out, taking advantage of a combination of complementary techniques such as differential scanning calorimetry, matrix assisted laser desorption ionisation time-of-flight and small- and wide-angle X-ray diffraction. We show that polysorbate 80, having an unsaturated hydrocarbon tail, crystallises by the ethylene oxide chains in the headgroup. Polysorbate 20, 40, and 60, containing saturated hydrocarbon esters tails, crystallise not only by the ethylene oxide chains but also by their hydrocarbon tails. An analogous behaviour was observed for the PS non-ethoxylated equivalents, the sorbitan esters. Sorbitan esters with saturated hydrocarbon tails displayed a crystallisation of the tail upon cooling, whereas the sorbitan ester with unsaturated hydrocarbon tail displayed no crystallisation.

Place, publisher, year, edition, pages
Royal Society of Chemistry, 2020
National Category
Physical Chemistry
Identifiers
urn:nbn:se:mau:diva-17855 (URN)10.1039/d0ce00236d (DOI)000540811300012 ()2-s2.0-85086182704 (Scopus ID)
Available from: 2020-07-28 Created: 2020-07-28 Last updated: 2024-02-05Bibliographically approved
Projects
The effect of the extracellular lipid organisation on skin barrier function; Malmö University, Biofilms Research Center for Biointerfaces
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-5654-4339

Search in DiVA

Show all publications